Small fixes to the QList documentation

Change-Id: Ic839f7859912eb48bb192755d6f10536a0a73f8e
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>

src/corelib/doc/snippets/code/src_corelib_tools_qlist.cpp

@@ -206,5 +206,5 @@ QList<double> list = QList<double>::fromStdVector(stdvector);
 QList<double> list;
 list << 1.2 << 0.5 << 3.14;
 
-std::vector<double> stdlist = list.toStdVector();
+std::vector<double> stdvector = list.toStdVector();
 //! [17]

src/corelib/tools/qlist.qdoc

@@ -592,9 +592,9 @@
     the list. From Qt 5.7, the capacity is preserved. To shed
     all capacity, swap with a default-constructed list:
     \code
-    QList<T> v ...;
-    QList<T>().swap(v);
-    Q_ASSERT(v.capacity() == 0);
+    QList<T> l ...;
+    QList<T>().swap(l);
+    Q_ASSERT(l.capacity() == 0);
     \endcode
     or call squeeze().